Koshiya, D. J.BHATT, HEMALKUMAR VINODRAI2018-05-212018-05-212004http://krishikosh.egranth.ac.in/handle/1/5810046919Investigations were carried out on succession of insect pests, their population dynamics and management in brinjal (Solatium melongena L.) at B. A. College of Agriculture, Gujarat Agricultural University, Anand during the year of 2001-02 and 2002-03. Siudy on succession of ir.portant insect pests and their natural enemies indicated that sucking pests viz; jassid , Amrasca biguttula biguttula Ishida; whitcfly, Bemisia tabaci Gennadius and aphid, Aphis gossypii Glover appeared during early vegetative stage and was active ihroughout the crop life span, whereas the activity of shoot and fruit borer, Leucinodes orhonalis Gtienee observed initially on shoots and subsequently on fruit during the fruit formation stage of the crop. The population of natural enemies viz; ladybird beetle Coccinella septempunctata L.; green lacewing, Chrysoperla carnea Steph. and geocoris bug, Geocoris ochropterus Fab. also coincided with their host population. A correlation study among the incidence of sucking pests and occurrence of natural enemies revealed that population of jassid and whitefly were positively correlated with ladybird beetle. Similar relationship was also observed between whitefly and predators green lacewing and geocoris bug. The study further indicated that peak population of aphid and jassid was (Miservcd when whitefly population was at its low level showing avoidance of competition among the sucking pests. Infestation of shoot and fruit borer, L orbonalis found throughout the Crop season. Initially, it was observed on tender shoots, then moved to fruits. Correlation study indicated that fruit damage had positive correlation with occurrence of green lacewing and geocoris bug. Similar association was found between aphid population and borer activity for shoot damage. A study on population dynamics of jassid revealed that pest appeared during third week of September and was active throughout the crop season. The highest population was recorded during fourth week of November. Correlation between population of jassid and weather factors (WF) was worked out. The study indicated that among the different physical factors of environment, maximum temperature (MaxT), evening vapour pressure deficit (VPD2)mean vapour pressure deficit (MVPD) and temperature range (TR) showed positive correlation, while negative correlation with evening relative humidity (RH2), mean relative humidity (MRH) and wind speed (WS). Regression study indicated that increase in MVPD (11 to 18 mm of Hg) and decreased in WS (4 to 2 KMPH) playing an important role for build up of the jassid population. Thus, dry atmosphere with low wind speed favoured the build up of the population. Infestation of whitefly, (B. tabaci) commenced from third week of September and reached to its highest level during December. Among the different physical factors of environment MaxT, minimum temperature (MinT), mean temperature (MT), morning vapour pressure (VPl), evening vapour pressure (VP2) and WS showed negative correlation with whitefly population indicating that population of this pest increased with decreased in Min T (17° to 10° C) and it flourished well in cold weather. Population of aphid, A. gossypii was active from third week of September to second week of January. During this period population showed violent fluctuations with three different peaks. Correlation study between population of aphid and WF revealed that bright sunshine hour (BSS) and WS showed negative correlation with pest population. The study further indicated that decrease in magnitude of BSS in the range of 9 to 7 hours proved favourable for the build up of pest population. It suggesting that cloudy weather favoured the build up of its population. Activity of shoot and fruit borer (L. orbonalis) found throughout the crop life span. Damage to shoots commenced from third week of September was maximum during last week of October. After fruit formation, it moved to fruits and the highest fruit damage observed during the month of December. Correlation study indicated that shoot damage showed positive correlation with MaxT, MinT, mean temperature (MT), morning relative humidity (RHl), VPl, VP2, mean vapour pressure (MVP), evening vapour pressure deficit (VPD2) and MVPD. Similar study for fruit damage revealed that MaxT, MinT, MT, RH2, MRH, VPl, VP2, MVP, morning vapour pressure deficit (VPDl) and WS showed negative correlation, which indicating that decreased in Min T between the range of 23° to 15° C proved favourable for this pest. A study on screening of sixteen genotypes/varieties of brinjal for their susceptibility against major insect pests during kharif season revealed that genotypes/varieties JB-64-1-2, GBH-1, Doli-5, AB-99-16, GBL-1, H-7, JBPR-98-2, Brinjal Castor Long and H-8 proved to be resistant to jassid, whereas Brinjal Green Round, Junagadh Long, Junagadh Oblong, PLR-1, AB-00-7 and AB-99-32 found moderately resistant by registering low jassid population. The population of whitefly was found low in genotypes/varieties Brinjal Green Round, GBH-1, Doli-5, Junagadh Long, Junagadh Oblong, JB-64-1-2, AB-99-16, JBPR-98-2 and GBL-1 and found to be resistant, whereas genotypes/varieties JB-64-1-2, AB-99-16, GBH-1, Doli-5, Brinjal Green Round, PLR-1, Brinjal Castor Long, JBPR- 98-2 and H-8 exhibited lower aphid population and showed resistant reaction to this pest. Further, a study on effect of morphological characters and biochemical contents of brinjal leaves on sucking pests indicated that hair density and hair length on leaves as well as thickness of midrib and lamina and leaf area are the important characters for imparting resistant to brinjal. Similarly, total soluble sugars, amino acids and total phenols of brinjal leaf provide basis for the resistance. Observation on shoot damage due to L. orbonalis revealed that genotypes/varieties Brinjal Green Round, GBH-1, H-7, Doli-5, JB-64- 1-2, AB-99-16, Brinjal Castor Long and H-8 proved to be resistant, whereas low fruit damage was recorded in genotypes/varieties JB-64-1-2, GBH-1, Doli-5, Brinjal Castor Long, Brinjal Green Round, H-7, H-8, Junagadh Long and PLR-1 and found resistant against this pest. Study on effect of morphological characters and biochemical contents of fruit revealed that morphological characters had no any effect on fruit damage, however, total soluble sugars, amino acids and total phenols play a vital role in imparting resistant to this pest. The yield data clearly indicated that a genotypes JB-64-1-2, GBH-1 and Doli-5 which proved resistant to sucking pests as well as shoot and the fruit borer and also registered the higher marketable fruit yield. A field study on evaluation of different newer insecticides for the control of pest complex of brinjal indicated that carbosulfan 0.025, monocrotophos 0.04, difenthiuron 0.05 and endosulfan 0.07 per cent effectively suppressed the jassid population. It has been further observed that whitefly population effectively controlled by difenthiuron 0.05, endosulfan 0.07, monocrotophos 0.04 and carbosulfan 0.025. Treatments with azadirachtin 0.00012 per cent found almost ineffective in controlling both the sucking pests. The results further revealed that all the insecticidal treatments proved significantly superior in reducing fruit damage due to L. orbonalis. However, carbosulfan 0.025 recorded the minimum fruit damage and was at par with monocrotophos 0.04 and endosulfan 0.07 per cent, whereas the treatment with azadirachtin could not prove effective in reducing the fruit damage. Yield data clearly indicated that plots treated with carbosulfan 0.025 registered the highest fruit yield (332.08 q ha-1), which was at par with monocrotophos 0.04 (322.64 q ha-1) and endosulfan 0.07 per cent (318.03 q ha-1). Considering the economics and efficacy of the treatments, monocrotophos 0.04, carbosulfan 0.025 and endosulfan 0.07 per cent gave appreciable net incremental cost benefit ratio (NICER) of 1:29.52, 1:26.54 and 1:22.32, respectively. Thus, these treatments can be recommended for the effective management of pest complex of brinjal.enAGRICULTURAL ENTOMOLOGY, AGRICULTUREA STUDYThesis